Speed control mechanism



Jan. 15,1952 w. w. CUSHMAN SPEED CONTROL MECHANISM Originl Filed Dec. 14, 1949 2 SHEETS-SHEET 1 INVENT OR ATTORNEY llll Jan. 15, 1952' w w, CUSHMAN 2,582,236

SPEED CONTROL MECHANISM Original Filed Dec. 14, 1949 2 SHEETSSHEET 2 -J L $6 1-) III x i 2/ A9 I I k 6 i I A3 M 2O ne /a /& iz7 1 4 1N VENT OR W W. Cu)? man ATTORNEY Patented Jan. 15, 1952 SPEED CONTROL MECHANISM Walton W. Cushman, Webb City, Mo.

Original application December 14, 1949, Serial N 0.

132,961. Divided and this application December 19, 1950, Serial No. 201,669

6 Claims. (01. 123-16) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 1 The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to speed control mecha-. nisms for engines and particularly internal combustion engines, and is a division of my application Serial No. 132,961, filed December 14, 1949,

for Rotary Internal Combustion Engine.

. A primary object of the invention consists in the employment of an automatically operated governor which is controlled centrifugally inaccordance with the R. P. M. of the rotor shaft throughout a wide range of operation and objviat'es the need for a conventional butterfly j throttle.

A still further object of the invention resides will be apparent from the following description l taken in connection with the accompanying drawings, in which,

f Figure 1 is a longitudinal sectional view through the rotary internal combustion engine taken onthe line I--I of Figure 3;

. Figure 2 is a fragmentary sectional view taken 'on line 2-2 of Figure 4;

Figure 3 is a vertical sectional view taken on line 33 of Figure l (partly in elevation) and looking in the direction of the arrows;

Figure 4 is an end elevational view (partly in section) taken on the line 4-4 of Figure 3 and looking in the direction of the arrows; Figure 5 is afragmentary end view of the engine looking in the direction of the arrows 5-5 of Figure I 3; and v Figure 6 is a fragmentary sectional view of the butterfly valve and its operating spring.

. In the present illustration of the rotary internal combustion engine thestator forms a part of the exterior casing and is of circular construction, and is indicated generally by the nu- 'meral I. Provided on opposite edges of the stator --is'apair of bosses 2, to which base members f 'or supports 3 may be securedas by bolts 4 for supporting the engine on a base or? thelike; al-

though it is to be understood that various conventional means may be employed for supporting the engine on a base or for suspending it by means of hangers.

The stator includes a disc-like casting I0, provided with a hollow bearing sleeve II, and provided also with a divider ring I0 having a series of recesses I2 to lighten the structure, and serving to provide lateral bearing surfaces for the rotor, as will appear hereinafter. The rotor is preferably formed of plated aluminum or other lightweight metal as is the stator, but cast iron has been successfully used on a hard steel shaft.

The shaft of this engine, in the present illustration is hollow and is indicated by the numeral I3. This shaft is rotatably mounted in the bearing I I of the stator, and is provided with an annular series of openings I 4, positioned just beyond the inner end of the bearing I I, so as to provide for the centrifugal discharge of live fuel into the interior of the engine as will appear later. Fixed to the outer end of the shaft I3, is the rotor I5, comprising a disc-portion I6, concentrically arranged on the shaft I3, as by means of the concentrically located hub II. Integrally formed on the innerface of the concentric disc I6, but eccentrically thereof, are inner and outer relatively concentric sleeves I8 and I9 having a width corresponding to the width of the divider ring I0 on the stator I0, so that the innerface of the disc I6 bears against the adjacent edge of the divider ring as indicated at 20 and the free ends of the concentrically arranged sleeves I8 and I9 bear against the innerface of the disclike portion of the stator ID, as indicated by numeral 2|. There is thus provided a rotor having an annular hollow portion which cooperates with the stator or divider ring ID to provide compression and combustion chambers as will later appear. It is to be noted that the hub H, which is fixed to the rotary shaft I3, is of such length as to provide an annular space between it and the inner end of the bearing II, so as to provide an annular passageway 22 for the exit of fuel through the openings I4 in the shaft.

The piston for the rotary engine is indicated by the numeral 23 and is provided with arcuate sides 24, adapted to be seated for oscillation in similarly curved bearing pads 25, which are mounted for reciprocation radially from the axis rotor as defined by the inner sleeve generally indicated bythe numeral- 31. This of rotation of the stator divider ring 19. By means of the reciprocally movable bearing pads, the piston is allowed to oscillate and radially reciprocate to the extent required by the passage of the eccentrically arranged rotor, it being noted that the inner and outer faces 26 and 2'! of the piston are curved to correspond to the curvature of the inner and outer sleeves of the rotor.

By reason of this eccentric mounting of the rotor it. will be apparent that a combined inductionand compression chamber 28 is provided as well as a combined combustion and exhaust chamber 29. To provide for the passage of compressed gases from the compressionchamber-dt to the combustion chamber 29, the piston 23 may be provided with a plurality of passages as, communicating at their outer ends with the compression chamber and at' their inner ends with a pocket 3i extending transversely of the piston and opening into an arcuate transverse slot 32 provided on the innerface of the rotor -55. "The piston 39 is also provided with a companion pocket 33 communicating with the inner ends of passages 34 formednat the opposite side and end of the piston and communicating with the combustion chamber 29. .With this arrangement,

' the pocket'3l through the medium of the passage- -way 30, is always'open to the reception of gases fromthe compression chamber, but such gases cannot betransferred fromthe pocket 3] to the 'pocket33, and thence to the combustion cham- "ber 29, until such time as the forward end of the arcuate slot-'32 inthe rotor passes the wall dividend of the slot passes beyondthe pocket St, the

, gases-compressed in the compression chamber are forced into thecombustion chamber 2%. The gases are ignited at each revolution of the engine; and in this sense, this rotary engine is or" *the-two-cycle type, but in another sense, provides four-cycle performance with complete, scavenging after each explosion. To ignite "the gases periodically-during each revolution of the engine, a glow plugtfi is provided and is positioned as indicated, (Fig. 2) so-that the gases will not be'fired in the combustion chamber. up

after the trailing end of the transfer slot 32 passes the partition 35 in the piston "23, therebyavoiding any possibility of the flames being carried into the compressionchamber.

In other wordsfthe glow plug will be'expos'ed to the live gases only when the rotor has moved around to such point that'the adjacent partof the sleeve -19 passes below the plug so thatthe latter is actually'within the combustion chamber. The timingof the engine may be controlled therefore by varying the radial position of the plug.

As already indicated, the fuel entering the hollow shaft is thrown by centrifugal force "through the openings I i, intothe interior of the l8, and

inner'sleeve I8 is provided with a plurality of openings'atl, extending through its wall and just behind these openings a combined scoop and impeller fifi may be provided for imparting a highly turbulent whirling action to the gases passing through the openings 54, and thereby causing them to-be-thrown by centrifugal force through the openings381into the induction and compression chamber 7-128. At relatively high speeds .thei -.gasesr.xmay. ;be. thrown through the openings 33 by such centrifugal force as to provide an intake charge having a pressure greater than atmospheric. Also, at relatively slow speed, the gases are inducted into the chamber 28 by the vacuum created therein, the amount of centrifugal force at such speed being relatively slight. Because of this centrifugal force, the engine is supercharged in the sense that the pressure of the gases forced into the chamber 28 is above atmospheric pressure; depending upon the speed. The outer sleeve it is provided with a series of exhaust openings Gt, through which the exhaust are discharged also by centrifugal force tendingto reduce the noise, and eliminate all back pressure on the exhaust stroke.

Threaded: to the left-hand end (Figure 3) of the hub of the stator it), as indicated by numer- 'al' il, is the manifold 42, to which the carburetor 3 is connected. Also associated with the outer end of the hub of the stator 56 is a thrust-bearing 46,- held in position by a nut 45, threaded .to the: outer. end of the hollow shaft l3, and it is to be notedthat this nut is threaded onto the shaft in a direction opposite to the direction of rotation of the rotor so that the inertia of the nut will serve to draw the rotor into closed relationship to the disc-like element'lil of the stator thereby automatically taking up any wear caused by the frictional engagement in the bearingsurfaceslw and 2| (Figure'B).

Mounted for pivotal movement within the shaft l3, as by means of pin, is a butterfly valve 41. Inthe specific construction illustrated the pin 46 is longitudinally slotted (Figure 6) and the valve 4'! is disposed in the slot so'that its center is at one side of the .pin. A tension spring 48 has an elongated portion 48f extended spect to the bolt 49. as the hollow shaft I3 is rotated during the operation'of theengine; The tension of the spring means "48 is so applied-to thepin 46 and butterfly valve as to normally bias the valve to open position, andthe-centrifugal force caused "by the rotation of the "shaft tends to move the valve '41 to closed position so that the valve and related parts act as a governor to maintain .the engine at a-predetermined speed. By adjusting the bolt [9 the amount of tension appliedto' the pin and-butterfly valve may be varied so :as to vary'the speed of the engine, as desired. The'oppositeend of the rotary shaft I3 is solid 'and'may have-applied thereto a pulley 52 or'other power take-off means; In the present illustration, the pulley '52 by'means of a keyway or similar device serves to interlock the rotary hub'll' with the shaft l3 and a nut-53 is threadedly connected'to this end of the shaft'tomaintainthese elements in interlocked "relationship.

;ing parts consists :in the use of armoderate amount :of. oil contained in. the air.:andi=gasoline -5 mixture passing into the interior of the rotary shaft, and this oil automatically finds its way through the oil apertures 54 to the several parts requiring lubrication.

The engine illustrated herein is air cooled and for this purpose the stator I is provided with a casing 55 having an air outlet 55, while the rotor I is provided with a, casing 56 fixed to rotate therewith and this casing as well as the casing 55 serve to provide air passages around such elements. The casing 56 is provided with an annular entrance opening 51 and a series of -fins or vanes 58 are mounted between the body of the rotor I5 and the inner wall of the casing 56, and these vanes serve as impellers in drawing large quantities of air through the annular opening 51. Likewise, the casing 55 is provided with radially extending fins or vanes 55". The air entering the casing between the vanes 58 passes about the outer surface of the rotor and about the disc-like portion I0 of the stator and thence out through the discharge opening 56 in the casing 55. It will thus be seen that provision is made for pumping large quantities of cooling air entirely about the exterior of the engine, so as to maintain it at a relatively low temperature. Internal cooling is effected by the incoming gases.

The operation of the engine has been fairly well described in connection with the description of the several parts thereof. It may be well, however, to briefly describe a complete cycle of operation of the several elements as they relate to each other. Assuming that the screw bolt 49 has been adjusted to produce the desired tension in the spring means 48 so as to cause the governor 41 to maintain the engine speed at the desired R. P. M. and electric current sent through the flow plug 36, the engine may be started in any preferred manner such as a coiled rope associated with the shaft I3 or by a blank cartridge placed in the combustion chamber 29.

The rotation of the rotor about the stator causes the formation of the induction and compression chamber which is somewhat smaller than the combustion chamber, thus allowing for more complete expansion of gases prior to the discharge of the exhaust to the atmosphere. The unburned gases are drawn by suction through the openings I4 over the shaft I3 into the compartment 31 which is encircled by the sleeve I8 of the rotor. From thence the gases are drawn through the openings 38 of the sleeve I8 into the compression chamber 28 of the engine. The continued rotation of the rotor decreases the size of the chamber, thus applying pressure to the gases prior to their transfer and entrance into the combustion chamber 29. These compressed gases pass into passageways 30 of the piston 23 and into the pocket 3| thereof. However the transfer of the compressed gases to the combustion chamber 29 cannot take place until the leading end of the transfer slot 32 passes the partition 35 between the two pockets 3| and 33. As soon as the leading end of the slot 32 passes the partition 35 the gases pass into the combustion chamber 29 and continue to be forced into this chamber until such time as the trailing end of the transfer slot 32 arrives at the partition 35. Communication between the combustion chamber 29 and the fuel chamber 31 is automatically cut off at this point because of the position of the rear end ofthe slot 32 with respect to the partition 35, and it is at this point that the glow plug is exposed to the gases and explodes or burns them within the chamber 29. It is :the expansion of these gases which acts against the relativelyfixed piston 23 and related parts of the stator and rotor to give a torque impulse to the rotor. As the speed of the engine increases the centrifugal force caused by its rotation progressively and gradually closes the valvegovernor 41 until the engine stabilizes at a speed for which the spring 48 is adjusted. During this increased speed of the engine centrifugal force comes into play to augment the suction heretofore referred to and throws the gases through the openings I4 of the shaft I3, and additional centrifugal force is applied to the gases by reason of the whirling action imparted to them by the rotation of the sleeve I8 and the whirling action may be increased by the employment of the scoop-impeller 39. The gases will thus be forced out through the outlets 38 into the induction and compression chamber 28, and as heretofore referred to are then forced into the combustion chamber at pressures substantially above atmospheric. The exhaust gases pass out through openings 45 in the sleeve I9, and their passage is augmented by centrifugal force. Since there is only a very small reversal in the mass of moving parts, relatively high compression ratios have been used (11:1) without detonation. This cycle of operation is of course rapidly repeated throughout the continuation of the operation of the engine.

The structural features of the engine are claimed in my earlier application identified above, and the claims of this divisional application are limited to the mechanism for controlling the engine speed automatically through the medium of the spring-operated valve 41 which is located in the hollow shaft l3 and therefore adapted to be biased toward closed position by centrifugal force.

In accordance with the patent statutes, I have described what I now consider to be the preferred form of automatic engine control, however, it is to be understood that the present disclosure is intended as illustrative of the invention rather than in any limiting sense, and that the control mechanism may be incorporated in various other types of rotary engines than that disclosed herein.

I claim:

1. A rotary internal combustion engine including a hollow rotary shaft; a fuel supply communicating with one end of the hollow shaft, a valve in said shaft adapted to be closed by centrifugal force, and a spring for biasing said valve to open position.

2. A rotary internal combustion engine including a hollow rotary shaft, a butterfly valve in said shaft, a pin extending transversely of the shaft and pivotally mounting the valve, and a spring for biasing the valve to open position.

3. A rotary internal combustion engine including a hollow rotary shaft, a pin extending transversely of the shaft, a butterfly valve eccentrically mounted on the shaft, and a spring for biasing the valve to open position.

4. A rotary internal combustion engine including a hollow rotary shaft, a fuel supply casing associated with an open end of the shaft, a butterfly valve mounted in the shaft, spring means connected to the butterfly valve and extending to the exterior of the casing, and means for adjusting the tension of said spring.

5. A rotary internal combustion engine including a hollow rotary shaft, a fuel supply casing associated with an open end of the shaft, a

butterfly valve mounted in the shaft, spring 

